What happened
On a clear afternoon near Blouin Lake, Quebec, a float-equipped Tierra II ultralight, registration C-IFHO, crashed during a pleasure flight. The flight began with several unsuccessful takeoff attempts. During one of these attempts, the aircraft's right float lifted first, causing the left wing-tip to strike the water's surface. After the contact, the pilot successfully became airborne and flew in a southwesterly direction before turning northeast and then following the lake's west shore.
While cruising at an altitude of approximately 400 feet, a loud noise signaled a structural failure. The left wing folded upward and toward the rear of the fuselage, causing the aircraft to descend rapidly and rotate into the ground. The impact resulted in two fatalities, as both the pilot and the passenger were killed upon impact. The aircraft sustained substantial damage.
The investigation
Investigators examined the wreckage and the aircraft's maintenance history. The Tierra II had a history of previous accidents and engine failures. Notably, the investigation identified significant assembly anomalies and unauthorized repairs. The left main wing spar had been replaced with a component that was smaller in diameter than the manufacturer's specifications, and the attachment points at the fuselage had not been modified to accommodate this smaller spar. This discrepancy resulted in a smaller wing chord on the left side compared to the right.
Engine and propeller examinations confirmed the engine was functioning at the time of the failure. Additionally, toxicological testing of the pilot's urine revealed the presence of cocaine and cocaine metabolites, though the timing of consumption could not be established.
Findings
- The left wing failed in flight due to a pre-existing structural weakness.
- This weakness may have been triggered when the left wing-tip struck the water during the initial takeoff attempt.
- The use of a non-specification, smaller diameter spar on the left wing, combined with unadjusted attachment points, likely created internal structural stresses.
- The pilot was not licensed to carry a passenger on this flight.